Alkyl b-D-glucosides (CnGlu) with different alkyl chain lengths (n ¼ 1, 2, 3,., 12) were prepared and the influence of the hydrophobic chain length on their thermotropic and glass transition behaviors was studied using differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction analysis (XRD). In the heating process of crystalline CnGlu (n $ 7), two distinct transitions between the solid and the lamellar liquid crystalline (LC) phase at melting point (T m ) and between the LC phase and the isotropic liquid (IL) at the clearing point (T c ) were observed. T c of C6Glu was observed monotropically at lower temperature than T m . When the non-crystalline alkyl glucosides were rapidly cooled, the glass transition was ascertained for all glucosides. In the case of CnGlu (n $ 6) a glassy LC phase, the glass phase having anisotropy like lamellar phase, was formed. The glass transition temperature (T g ) lowered until the chain length reached C5 because of the reduction of the hydrogen bonding networks, while further increase of the chain length did not affect T g irrespective of the of number of the hydrophobic chain length (n $ 5). When CnGlu was supercooled at room temperature, which is between T m and T g , XRD measurements showed that there was no structural difference in the glucose moiety working as a hydrophilic group in the resultant LC phase. It indicates the importance of the hydrogen bonding between the hydrophilic sugar moieties on the glass transition behavior of n-alkyl b-D-glucosides. Chart 1 Chemical structure of alkyl b-D-glucoside (CnGlu) used in this study.
The effect of polymers on the ice nucleation temperature (T f ) was studied in a W/O emulsion using ~ 5m diameter droplets by differential scanning calorimetry (DSC). Four types of polymers were used. Among them, only polyvinyl alcohol (PVA) showed the additional effect of increasing the T f of the aqueous solutions. This increase was logarithmic with the concentration of PVA and the difference in molecular weight did not have any significant effect on T f for the same weight concentration. It was shown that the number of the structural unit (CH 2 CHOH) was the key parameter for the increasing degree of T f .
The preparation of model, well-controlled colloidal assemblies has been a central approach to understanding and optimizing the characteristics and functionality of complex colloidal dispersion systems. This approach, which has created a significant literature and rather deep understanding for emulsions and foams, has yet to be established for the liquid marble (water-in-air) motif. In this article we report the preparation of well-controlled liquid marbles using monodisperse micron-size particles of poly(methylsilsesquioxane) (PMSQ). The low cohesive nature of the stabilizing particles, their narrow size distribution, and their hydrophobicity permit the formation of liquid marbles containing a particulate monolayer with a hexagonally close-packed (HCP) structure. The "cleaning process" by rolling of liquid marbles under a flow of air on a hydrophobic substrate was useful to obtain the monolayer structure. Moreover, the monolayer structure was only obtained from liquids with high surface energy, whereas the others were not useful even though multilayered structure was formed from liquids that have intermediate surface energy.
Despite the significance of synthetic monotailed β-linked galactolipids, for a detailed understanding of natural galactolipids, many aspects of these β-linked galactolipids' crystal structures such as temperature-dependence and hydration characteristics remain inadequately understood. In this manuscript, we demonstrated detailed insight of crystal characteristics of one of the simplest monotailed galactolipids, octyl-β-d-galactoside (MOβ-Gal), using thermal analyses, Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) measurements and grazing-incidence wide-angle X-ray diffraction (GI-WAXD) analysis. As a result, it was revealed that the MOβ-Gal anhydrous crystal showed a continuous structural change from the high-symmetry structure to low-symmetry crystal lattice via the strengthened hydrogen bonding interaction as the temperature decreased. In addition, the hemihydrate crystal was found to be in the modulated "ribbon phase". These insights strongly suggest that β-linked galactolipids possess intrinsic characteristics necessary to form a modulated structure even in the crystal state and demonstrate the importance of the presence of tiny amounts of water as cushioning media for preventing order parameter evolution.
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